Bonded building block assembly

ABSTRACT

My invention consists of seamless facings bonded onto all types of concrete masonry units, also known as concrete block, used for constructing walls. Facings are cast, formed, molded, or deposited onto ordinary concrete block after it has been manufactured, but before it is delivered for construction. The primary intent is to transform ordinary block into masonry units that have profiles and shapes that are not otherwise available as concrete masonry products. Profiles and shapes are devised that preserve the modular characteristics of concrete masonry.

CROSS-REFERENCE TO RELATED APPLICATIONS

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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

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THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

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INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK

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BACKGROUND OF THE INVENTION

A. Technical Field

My invention is related to unit masonry; more specifically, concrete masonry units, laid up together using mortar to form walls. Already-manufactured concrete masonry units are overlaid with molded facings.

B. Background Art

Prior art related to my invention falls into four categories, each of which is discussed below.

1. Concrete Masonry Units

Concrete masonry, also known as ‘concrete block’, or simply ‘block’, is an economical way of constructing fire-resistant self-supporting and load-bearing walls. Sadly, at the expense of appearance and durability, common concrete block is used for exterior, exposed-to-view and exposed-to-weather applications. It is a low-cost alternative to walls traditionally constructed of stone or brick. Common concrete block has a coarse texture that gives it a dreary, unfinished appearance and relatively high water absorption.

In response to the desire for more attractive concrete masonry units for use in exterior walls, the concrete masonry industry has developed units with more decorative surfaces. Those most commonly available are split-faced, ribbed-faced, grid-block, and ground-faced. Split-faced blocks have a rough, uneven surface that resembles a broken stone. Split-faced blocks are produced by casting two or more units together across the intended decorative faces and cleaving them into individual units after the curing process has begun. Ribbed-faced blocks have vertical striations similar to corduroy. Striations are formed by the block molds during the casting process. Heavily striated versions are also cast face-to-face and split apart. Grid block is cast with a vertical false mortar joint, giving the illusion that the wall is made of square units arranged in a grid. Ground-faced block has polished exposed surfaces, emphasizing the aggregates used in the mix. Declining in popularity are slump block and tapered geometrics. None of the patterns mentioned above incorporate undercuts, which are necessary to produce the rusticated profile preferred for my invention.

Some older buildings feature styles of decorative block that no longer seem to be available. One type has a multi-faceted uneven surface that resembles rough-hewn stone, similar to a slump block but more pronounced. Another has the rusticated profile that I prefer for my invention, although it is a somewhat crude approximation of rustication. Both styles require undercuts in the exposed vertical faces, so one-piece molds made to slip up off the units after casting would not have worked. Nonetheless, the decorative facings were integrally cast with the block.

Decorative concrete block styles have gained acceptance for use in exterior walls. The bonded block assembly of my invention is an alternative to the decorative units offered by the concrete masonry industry, which are limited by the capabilities of the slip-casting process employed for mass-producing block.

2. Natural Stone

The profile I prefer for my invention mimics dressed rusticated stone. Natural stone, such as granite, limestone and sandstone, would be the preferred material for constructing walls in the rusticated style. Stone is quarried, cut and dressed into a wide range of size and shape. When you see a wall of rusticated masonry, you should assume it is made of stone. Stone unit masonry is expensive and is entirely appropriate, as it has always been, for monumental structures.

3. Pre-Cast Concrete Units

Pre-cast concrete is currently produced to resemble stone and is available in the form of solid units and as a thin applique. The beveled-edge profile of rusticated masonry works well for pre-casting, since it eliminates sharp, brittle corners.

Solid pre-cast concrete is made-to-order in custom shapes and sizes and is a suitable alternative to stone. It is used predominately for massive structural headers (or lintels), and decorative sills, wall caps and trim. Although solid pre-cast concrete can be made in virtually any profile, including the profiles I have illustrated, an entire wall made of solid pre-cast concrete units has not been shown to be very practical and I doubt one could easily be found.

Pre-cast concrete appliques are marketed as a more economical substitute for the look of stone. Appliques consist of wafer-like decorative concrete parts that are applied to masonry or stucco walls after they have been erected. Parts are installed using the same thin-set method used to set ceramic tile. Appliques can usually be identified as such at corners, joints and edges, although single-piece wrap-around corners are sometimes available. Appliques look especially unauthentic if the installer is unable to align the applique joints or perimeter edges with joints in the adjacent field of masonry or has to cut applique parts because of inadequate advanced planning. Like solid pre-cast, pre-cast applique is not very practical for use on an entire wall, and is more likely to be reserved for trim.

4. Patented Masonry Units

Numerous patents exist for masonry units of various shapes. Many display rusticated profiles. There is also a patent for an applied facing. Existing patents generally fall into the categories of interlocking units and units with illusory false joints. None of the existing patents found involve applying a facing to already-manufactured block that includes comprehensive solutions for accommodating corners and openings, angles and curves in a working relationship to modular masonry construction.

BRIEF SUMMARY OF THE INVENTION

The bonded block assemblies of my invention (bonded units, faced units, or units, for short) are novel, unlike any blocks that have been or are now available or that have been revealed in a patent search. The properties that set my invention apart are the combination of: its decorative effect and finished surfaces; its modularity; its ability to incorporate corners and openings, angles and curves; and its hollow, relatively light weight—all made possible by applying a facing to already-manufactured block. These are the qualities that set my invention apart from prior art.

My invention consists of facings that are cast, formed, molded or deposited onto utilitarian concrete masonry units (concrete block, or block, for short) of all types. The intention for providing such facings is, first and foremost, to expand the aesthetic possibilities of concrete masonry. A secondary benefit would be a possible improvement to its weatherability. Facings are bonded to concrete block after they are manufactured, but before delivery for construction. These facings, when thick enough, can transform blocks into units that have high-relief profiles and/or altered shapes. In any case, the units so transformed would be used for construction in the conventional manner; that is, laid up with mortar, typically in a running bond (whereby vertical mortar joints in alternating courses are staggered).

While it's unlikely that I'm the first to have tried molding a facing onto blocks, I believe I am the first to have devised comprehensive dimensional controls for doing so. The advantages of incorporating concrete block into my bonded block assembly are:

1. I get the benefits of the efficiency, quality control and product diversity already developed by the block-making industry.

2. I am able to provide a finished decorative surface that has undercuts without complicating the slip-form molding technique used to mass-produce cored block.

3. I can produce a structural unit that has some of the same custom shape capabilities the pre-cast concrete industry provides very simply with its pre-cast appliques but without the bulk and mass of solid pre-cast.

The bonded units illustrated have a profile that resembles dressed rusticated stone. They accommodate corners and openings and transform the shapes of blocks in a way that is consistent with the rusticated style. ‘Rusticated’ is not to be confused with ‘rustic’. ‘Rustication’ refers to a style of masonry that is actually quite refined, in which the mortar joints are accentuated by a wide or deep relief in and along the edges of the masonry units. This style of masonry has been used throughout the ages and is an important element in classical architecture. It continues to be used today, both in the form of natural stone and pre-cast concrete. Although developing a concrete block that could replicate the rusticated style was my goal as I was developing my invention, my invention has a wider scope. Applying a facing in order to modify the shape alone serves useful purposes even without incorporating a rusticated profile.

Importantly, the bonded units have configurations that do not violate the modular characteristic of concrete block work. The simple-to-use and easily understood modular system is promoted by concrete masonry manufacturers, masonry contractors, architects and engineers. Masonry work laid out and erected in sympathy with the modular system minimizes, and can even eliminate, the need for cutting and fitting odd sized masonry units at the job site. This results in a neat and orderly appearance of the completed wall. The bonded units described here not only respect, but take advantage of, the superior results obtained from modular planning and layout of masonry work.

The bonded units as devised include configurations appropriate for external and internal corners, jambs and heads of door and window openings, angled bays, and curved walls, all the while staying on module. I have developed molds to produce the facing configurations needed to accomplish this and have cast prototypical units. The molds enable seamless cast-in-place facings to be bonded to concrete block on any and all surfaces that would be exposed to view in a completed wall.

The facing material to be used for my invention can be any that have the physical properties needed to assure a durable surface with a desirable appearance. As such, they must be capable of being cast to shape, bond well to concrete block, be weather resistant, and shrink very little as they cure. My prototypes are made using masonry mortar as the facing material.

I describe the process and the result that together are the essence of my invention—utilitarian concrete block transformed by applying facings over surfaces that would be exposed to view, in configurations that produce deep-relief profiles and unusual shapes, while remaining true to the modular system. My invention transforms common concrete block into masonry units that can be used more creatively.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

My invention is graphically shown on eleven drawing sheets. Figures with a prefix of 1 are located on Sheet 1, with a prefix of 2 on Sheet 2, and so on; except that figures with prefixes 4 and 5 are found on either Sheet 4 or 5.

Definitions: The ‘front’ of a block or a bonded unit means the nominal 16″ long by 8″ high vertical surface that is exposed to view when it is laid up into a wall, or what remains of that surface if it has been cut to a smaller size. A ‘stretcher’ is a block or bonded unit that is, or is to be, laid up into the field of the wall so that the entire front face, but only the front face, is exposed to view. ‘Full-sized unit’ or ‘full unit’ means a unit that fills the entire 16″ by 8″ module once a mortar joint has been added. ‘Half-sized unit’ or ‘half unit’ means a unit that fills the 8″ by 8″ half module once a mortar joint has been added.

Sheet 1 shows isometric drawings of a few modular bonded units. Blocks are shown before and after receiving the bonded facings. FIGS. 1 a, 1 b, 1 c, 1 d, 1 e and 1 f show blocks before they have been faced. FIGS. 1A, 1B, 1C, 1D, 1E and 1F show bonded units after they have been faced. Drawings of blocks before they have been faced also show any portions of the blocks that are removed before the facings are applied. Concrete block can easily be cut using diamond or abrasive wheels and cuts done in the shop can be made accurately and cleanly.

Sheet 2 shows front and plan views of faced units for the four key modular configurations needed: basic straights (stretchers), outside corners, jambs (for openings through the wall), and inside corners. FIGS. 2A and 2 a are front and plan views, respectively, of a stretcher. FIGS. 2B and 2 b are front and plan views of an outside corner unit. FIGS. 2C and 2 c are front and plan views of a jamb unit. FIGS. 2D and 2 d are front and plan views of an inside corner unit. Stippling is used to differentiate the facings from the blocks to which they are applied. Dashed lines that surround the units are module lines.

FIG. 3 on Sheet 3 shows a large-scale plan that demonstrates how the four key configurations shown on Sheet 2 fit into the modular grid (shown dashed) and fit with each other. Once again, stippling is used to differentiate the facings from the blocks to which they are applied.

Sheets 4 and 5 show front and plan or end views of a more complete set of modular configurations, expanded to include the various combinations of corner and jamb profiles in both full-sized and half-sized versions. FIGS. 4A and 4 a show front and plan views, respectively, of a full-sized stretcher unit that has received the facing preferred for my invention. FIGS. 5A and 5 a show the half-sized stretcher. FIGS. 4B, 4 b, 5B and 5 b show the full- and half-sized outside corner units. FIGS. 4C, 4 c, 5C and 5 c show the full- and half-sized double corner units. FIGS. 4D, 4 d, 5D and 5 d show the full- and half-sized jamb units. FIGS. 4E, 4 e, 5E and 5 e show the full- and half-sized double jamb units. FIGS. 4F, 4 f, 5F and 5 f show the full- and half-sized combination outside corner-and-jamb units. FIGS. 4G and 4 g show the inside corner unit. FIGS. 4H and 4 h show the combination inside corner-and-jamb unit; FIG. 4 hh shows an alternative for FIG. 4 h. FIGS. 4J and 4 x show the front view and plan, respectively, of the full-sized lintel unit; FIGS. 5J and 5 x show the front view and plan of the half-sized lintel unit; FIGS. 5K and 5 x show the front view and plan of the double-height lintel unit; Figure Xj shows an end view of FIGS. 4J and 5J; and Figure Xk shows an end view of FIG. 5 k.

Sheet 6 shows isometric drawings of a few angled bay corner units and bowed-front units. Blocks are shown before and after receiving the bonded facings. FIGS. 6 a, 6 b, 6 c, 6 d, 6 e and 6 f show blocks before they have been faced. FIGS. 6A, 6B, 6C, 6D, 6E and 6F show bonded units after they have been faced. Drawings of blocks before they have been faced also show any portions of the blocks that are removed before the facings are applied.

Sheet 7 shows plans of angled bays laid out using bonded units with angled corners. FIG. 7 shows walls laid out with 60° and 45° angled bays. Wrap-around corner units align with the bay angles. The capability of my invention to incorporate out-of-square corners can also be utilized when it is desirable to construct walls along irregular property lines.

Sheets 8 and 9 show plans of curved walls of various radii laid out using bonded units with bowed front surfaces. FIG. 8 shows curved walls laid out with bowed-front units that accommodate arc sweep increments of 90°—useful for creating turrets, pilasters and pillars. FIG. 9 shows curved walls that accommodate arc sweep increments of 60°—useful for bows. In all cases, the curvatures of the facings match the curvatures of the arcs.

Sheets 10 and 11 show example walls, in front view and plan, utilizing bonded units. Dashed lines evenly spaced along the bottom of both sheets are 8″ module lines, intended to demonstrate the relationship of the example walls to the masonry module. FIG. 10 is a front elevation view of a wall that incorporates conventional 90° corners and a 45° angled bay; FIGS. 10 a and 10 b are plan views of the masonry courses indicated by the section marks shown on FIG. 10. FIG. 11 is a front elevation view of a wall that incorporates a turret, bow, pilaster and pillar; FIGS. 11 a and 11 b are plan views of the masonry courses indicated by the section marks shown on FIG. 11.

DETAILED DESCRIPTION OF THE INVENTION A. Drawings

Figures on Sheet 1 show a series of units used for modular rectilinear walls. Shown are isometric views of modular 8″ wide (or thick, front-to back) blocks before and after they have received the seamless bonded facings. Figures with lower-case letter suffixes show blocks before they have received the facing; those with upper-case letter suffixes show the same blocks after they have received the facing.

FIGS. 1 a and 1A show a full-sized stretcher unit before and after it has received the bonded facing.

FIGS. 1 b and 1B show a full-sized outside corner unit before and after it has received the bonded facing that wraps around the corner. This unit is used for constructing outside corners in walls. This facing, like all others that have been developed, is seamless across all surfaces and as it turns the corner.

FIGS. 1 c and 1C show a full-sized jamb unit before and after it has received the bonded facing that wraps around the corner and into the jamb. This unit is used for the jambs of openings through walls, such as occur at doors and windows. Since best practice calls for doors and windows to be recessed into the wall in order to protect them from the weather, the wall surfaces that return into the opening are partially exposed to view, and that is why the jambs need to be faced. Prior to receiving the facing, the stub end (ear) of the block's face shells are cut back to allow clearance for the material that faces the jamb end of the unit, keeping the transformed unit true to the 16″ module length. The result is a finished jamb surface.

FIGS. 1 d and 1D show a full-sized inside corner unit before and after it has received the bonded facing that partially covers the front of the block. This unit is used for constructing inside corners in walls.

FIGS. 1 e and 1E show a U-shaped lintel (bond beam) unit before and after it has received the bonded facing that wraps underneath. This unit is used at the heads of openings through walls. Prior to receiving the facing, the top edge of the block's face shells are cut off to compensate for the material that faces the underside of the unit, keeping the transformed unit true to the 8″ high coursing module. The transformed unit is used the same way that the manufacturer of the block intends. Horizontal steel reinforcing bars are positioned in the long U-shaped hollow created when multiple units are laid end-to-end to span an opening through the wall. The hollow is then filled with grout. After the grout has cured sufficiently, temporary shoring that supports the lintel units can be removed. The result is an overhead masonry lintel (beam) with a finished underside.

FIGS. 1 f and 1F show a full-sized stretcher unit cut down to a half-sized unit, before and after it has received the bonded facing.

Figures on Sheet 2 are drawings of the four key modular bonded block assemblies of my invention. Figures with upper-case letter suffixes are front views; those with lower-case letter suffixes are plan views. Dashed lines that surround the figures are module lines, which by convention lie along the center of a standard ⅜″ mortar joint used for laying block.

FIGS. 2A and 2 a show the basic full-sized stretcher unit. For this unit, typically needed in the largest quantity, only the front of the block receives the facing. The facing is framed by a chamfer (bevel). The thinnest portion of the facing, which runs along the perimeter of the chamfered edge, is always 3/16″. Not coincidentally, this is half the thickness of a standard mortar joint. From that 3/16″ thick starting edge, the facing begins its chamfered profile, always at a 45° angle to the front surface of the facing. This is the geometry that makes modular inside corners successful for the substantially thick facings I prefer for my invention, and it follows through for all of the various configurations. The chamfer I have shown is 1″ deep. I selected it for convenience and like the proportions it gives to the profile. The total thickness of the facing is therefore 1 3/16″.

FIGS. 2B and 2 b show the full-sized outside corner unit. The facing wraps around the corner of the block and the chamfered profile appears on both the front and end of the block. The facing is symmetrical about the corner. Outside corner units have the most complex shape. Nonetheless, I have successfully cast them without a seam.

FIGS. 2C and 2 c show the full-sized jamb unit. While the minimum 3/16″ thick edges and 45° chamfered profile hold true on the front, the facing on the end that returns into the jamb has a flat profile in order to provide a flush surface for installing door and window frames. The facing returns seamlessly into the jamb.

FIGS. 2D and 2 d show the full-sized inside corner unit. The bonded facing extends approximately half the length of the front of the block. Actually, it ends 3/16″ short of the blocks' midpoint, the importance of which can be understood by examining FIG. 3.

FIG. 3 is an enlarged plan of the four key bonded units shown on Sheet 2 arranged overtop an 8″ by 8″ grid (dashed lines). Two-character identification marks (2 a, 2 b, 2 c and 2 d) placed on the units refer back to the Figures so identified on Sheet 2. FIG. 3 demonstrates how the units are able to maintain the 16″ module and 8″ half-module. It can be seen that the chamfered facing profile remains consistent all along the exposed surfaces of the wall. Jamb units provide a flat finished surface without trespassing into the modular-sized opening. The 3/16″ minimum thickness of the facing at the perimeter of the chamfered edges and the symmetrical conditions at the outside corner and about the joint at the inside corner can clearly be seen. The modular grid illustrates that mortar joints are always centered on module lines, as they should be. This is no different than the way un-faced modular block would be laid. The proper and successful use of my invention is dependent upon the ability and willingness of designers and installers to confine themselves to a modular layout so that units' bonded facings don't have to be cut. It would be unreasonable to expect a faced block to be cut and beveled freehand on the job site without getting an objectionable result.

Figures on Sheets 4 and 5 are arranged with full-sized and half-sized versions of the various bonded units. Two-character Figure numbers with a 4 as the prefix show full-sized units; 5 is the prefix for half-sized units. Figures denoted with upper-case letter suffixes show the front view. Figures with the same suffix letter in lower-case show the associated plan view, as in 4A and 4 a for the full-sized basic stretcher, front and plan views. The set of units shown on these two sheets should be adequate to satisfy all the conditions that would normally be encountered in square-cornered rectilinear walls with openings.

FIGS. 4A, 4 a, 5A and 5 a show the basic full- and half-sized stretcher units. The full-sized version has been described in detail in the description for FIG. 2A.

FIGS. 4B, 4 b, 5B and 5 b show full-and half-sized outside corner units. The full-sized version has been described in the description for FIG. 2B.

FIGS. 4C, 4 c, 5C and 5 c show full-and half-sized double outside corner units, in which the chamfered facing profile wraps seamlessly around three sides.

FIGS. 4D, 4 d, 5D and 5 d show full-and half-sized jamb units with one end faced for use along the jamb of a window or door opening. The full-sized version has been described in the description for FIG. 2C.

FIGS. 4E, 4 e, 5E and 5 e show full-and half-sized double jamb units with both ends faced for use where window or door openings occur at both ends of the unit.

FIGS. 4F, 4 f, 5F and 5 f show full- and half-sized combination outside corner-and-jamb units with the end opposite the outside corner faced for use along the jamb of a door or window opening. (The half-sized version of this unit serves no practical purpose; an opening can't normally be located that close to an outside corner because it leaves no clearance for finishes on the inside.)

FIGS. 4G, and 4 g show an inside corner unit. This unit has been described in the description for FIG. 2D.

FIGS. 4H, and 4 h show a combination inside corner-and-jamb unit with the end faced for use along the jamb of a window or door opening. I expect that this unit will be too difficult to cast; I haven't devised a way to register the block onto the mold. For all practical purposes, it can be replaced by the combination shown in FIG. 4 hh, in which a half-sized jamb unit (5 d) is backed up at the inside corner by a plain half-sized block.

FIGS. 4J and 5J show front views of full- and half-sized U-shaped lintel (bond beam) units. FIG. 5K shows the front view of a double-height lintel unit. FIG. 4 x shows the plan view of FIG. 4J. FIG. 5 x shows the plan view of FIGS. 5J and 5K. Figure Xj shows the end view of FIGS. 4J and 5J. Figure Xk shows the end view of FIG. 5K. End views show that the units are faced on the underside for use over a door or window opening and show two steel reinforcing bars positioned near the bottom of the hollow channel, as is customary. The plan views look down into the hollow channel that is meant to receive steel reinforcing and grout. See the description for FIG. 1E for additional details. The two-course high lintel unit shown in FIGS. 5K and Xk is not always available. It is used where a lintel of very high load-carrying capacity is needed. It is nominally 8″ long and 16″ high, equivalent to a full-sized unit standing on end.

Figures on Sheet 6 now show units to be used for angled bays and curved walls. Shown are isometric views of blocks before and after they have received the bonded facings. Figures with lower-case letter suffixes show blocks before they have received the facing; those with upper-case letter suffixes show the same blocks after they have received the facing.

FIGS. 6 a and 6A show an outside corner unit used for constructing 60° angled bays. A full-sized modular block, without any cutting required, is faced to produce a 60° outside corner unit and the angled bay created by it will always be on module, as will be demonstrated by FIG. 7.

FIGS. 6 b and 6B show a combination outside corner-and-jamb unit used for constructing 60° angled bays. The ears of the block's face shells are cut back in order to provide space for the facing to wrap around into the jamb.

FIGS. 6 c and 6C show an outside corner unit used for constructing 45° angled bays. The geometry of a 45° angled bay, as it relates to the masonry module, will be explained in the descriptions for FIG. 7. This unit would also be provided in a combination corner-and-jamb version (not shown).

FIGS. 6 d and 6D show a bowed-front unit before and after it has received the facing that makes it useful for constructing curved walls—turrets, bows, pilasters and pillars. The radius of the bowed face should match the radius of curvature of the wall for the best results. In every instance when blocks are faced for use in curved walls, both ends of the blocks have to be cut before receiving the bonded facing, and the blocks' core configuration needs to be selected with that in mind. Blocks have to be cut to length and both ends cut back at an angle in order to fit the way the designer divides the curved wall into individual units. FIGS. 8 and 9 will further illustrate this.

FIGS. 6 e and 6E show a bowed-front unit with the same shape and size as the unit shown in FIG. 6D, except that it is also provided with finished jambs at both ends. Additional material is removed from an end of the block in order to allow space for the facing to be applied along the jambs.

FIGS. 6 f and 6F show a bowed-front unit with facing that matches the curvature of units shown in FIGS. 6D and 6E, but with only half of the arc sweep of the larger units. It also has finished jambs.

Sheets 7, 8 and 9 show a variety of angled bays and curved walls in plan view, laid out using bonded units. Notations on the three sheets share the following conventions: Blocks shown by dashed lines and noted ‘F’ and ‘H’ are, respectively, full-sized and half-sized modular un-faced blocks, shown to demonstrate how the underlying modular principle carries through; Blocks shown by solid lines and noted ‘F’ and ‘H’ are full-sized and half-sized modular bonded units that have already been described on the first five sheets of drawings, shown in phantom (internal core structure omitted) so that attention may be focused on the specialized bonded units now being introduced and to demonstrate how angled bays and curved walls incorporate and transition to the modular bonded units already described.

FIG. 7 shows, in plan, how 60° and 45° angled bays can be constructed using the angled corner units shown as FIGS. 6A, and 6C on Sheet 6. Bonding additional material onto an ordinary concrete block provides an opportunity to construct bays that have wrap-around corners of the proper angle. Consider that presently, corners of angled bays are usually made by field-cutting miters on the ends of conventional masonry units so that they butt together at the corner, resulting in a vulnerable continuous vertical mortar joint at the corner. The bonded corner units I illustrate have the deep chamfered profile I prefer, however my invention should also apply to any profile used to create out-of-square corners, including those that are simple thin overlays on the front face.

The bay noted as 7-1 is a 60° angled bay. Units marked 7 a are corners. Corners are the only specialized shape needed to construct a 60° bay; the rest are full-size and half-size modular units already presented on the first five sheets. The ends of the bay will always be on module where the bay meets the surrounding wall (as demonstrated by the dashed modular blocks that extend through the bay). Corner unit 7 a, in order to conform to the modular system, has a nominal front face length of 16″ and a nominal angled-side face length of 8″. The angle between the front and side faces is 120°. The corner unit (7 a) would also be provided with a finished jamb (not shown) when necessary.

Bays noted as 7-2, 7-3 and 7-4 are 45° angled bays. A 45° bay (and any bay other than 60°) requires algebraic calculations to work out the nominal lengths of units that will keep the bay on module. For a 45° bay, corner unit 7 b needs to have a nominal front face length of 13¼″ and a nominal angled-side face length of 6⅝″, which is half of the length of the front face. The angle between the front and side faces is 135°. Units marked 7 c are stretchers cut down to a nominal length of 13¼″, the same as the length of the front face of the corner unit. Any bay made with 7 b and 7 c units will have an overall width equal to an even number of full-sized modular blocks (whole number multiples of 32″) as long as the lengths of the 45° splayed side walls of the bay are equal to the length of the front wall, as is the case for bay 7-2. Now that the ends of the bay 7-2 are on module, the total width of the bay can be increased without a corresponding increase in the bay's depth, as would often be desired, as illustrated by bay 7-3. Bays 7-3 and 7-4 show alternating masonry courses of a bay that has a front wall that is longer than the splayed side walls by 32″—two full stretchers. A close examination of bay 7-3 reveals that two full-sized stretchers have simply been added to the center of the front wall of bay 7-2. Bay 7-4 shows the next course of masonry for bay 7-3. Unit 7 d is nominally 6⅝″ long, which is half as long as unit 7 c. Unit 7 e has a nominal length of 14⅝″, which is equal to the length of unit 7 d plus 8″. Unit 7 e is necessary to maintain symmetry about the centerline of bay 7-4. Refer to FIG. 10 for a front view of a 45° angled bay that might better demonstrate the desirability of maintaining a balance about the bay center. The four specialized units needed for a 45° angled bay (7 b, 7 c, 7 d and 7 e) would also be provided with finished jambs (not shown) when necessary.

FIGS. 8 and 9 illustrate curved walls made with bonded block assemblies that have a bowed front facing. Shown are series of progressively larger radii of curvature, where the radius, measured to the swept-back edges of the chamfer, is always a whole number multiple of the 8″ half-module, ensuring an on-module transition to adjacent rectilinear walls. Consider that presently, curved walls constructed of masonry are almost always built with conventional straight-fronted masonry units with the result that curves are actually segmented approximations of curves; the tighter the radius of curvature in relation to the length of the masonry units used, the less satisfactory the results. The bonded bowed-front units I illustrate have the deep chamfered profile I prefer, however my invention should also apply to any profile used to create curved units, including those that are simple thin overlays. Bowed fronts afford the opportunity to be creative with curved walls without settling for segmented approximations or having to obtain customized curved units from the manufacturer, a request he probably won't honor in a timely manner, if at all. As can be inferred from FIGS. 8 and 9, a different set of molds has to be made for each curved wall radius intended, and each set would include whole-segment and half-segment arc units with and without finished jambs in various combinations (not shown). Because the curved chamfers of my preferred profile are conical surfaces, a high level of skill and sophisticated machinery are needed to make the mold patterns.

FIG. 8 shows a series of curved walls devised so that whole- and half-segment units fill one-quarter of a full circle. These are useful for constructing turrets, pilasters and pillars. Ring 8-1 has an 8″ radius and a faced whole-segment sweeps 180°, ring 8-2 a 1′-4″ radius with a 60° whole-segment sweep, ring 8-3 a 2′-0″ radius with a 36° sweep, ring 8-4 a 3′-4″ radius with 20° sweep, ring 8-5 a 4′-8″ radius with 15° sweep. Larger rings, not shown, would have a 6′-0″ radius with a 12° sweep, 7′-4″ radius with a 10° sweep, 10′-0″ radius with a 7½° sweep, and so on. Bonded units along rings 8-2 and 8-3 are made from 4″ wide (thick) block; units along larger rings are made from 8″ wide block. Units marked 8 a, 8 b and 8 c are so noted in order to cross-reference to the same units that appear in FIGS. 11 a and 11 b.

FIG. 9 shows a series of curved walls devised so that whole-segment units fill one-sixth of a full circle. These are useful for constructing bows. Arc 9-1 has 4 units arranged along a 4′-0″ radius for a bay width of 4′-0″, arc 9-2 has 6 units on a 6′-8″ radius and bay width, arc 9-3 has 8 units on a 9′-4″ radius and bay width. Similarly, but not shown, a 5′-4″ radius and bay width would have 5 units, 8′-0″ radius and bay width would have 7 units, 10′-8″ radius and bay width would have 9 units, and so on. The unit marked 9 a is so noted in order to cross-reference to the same unit that appears in FIG. 11 a.

Figures on Sheets 10 and 11 are front views and plans of example wall layouts using my invention of bonded block assemblies. The identifying tags placed on the various units refer to the unit configurations shown on other sheets. Thus, the identifying tag 4 g refers to the inside corner unit shown as FIG. 4 g on Sheet 4 or 5, the unit tagged 7 b is the same angled bay corner unit that is tagged as 7 b in FIG. 7, and so on. The layouts are on module without the need to field-cut any of the faced units. Dashed hash marks across the bottoms of the sheets are spaced at 8″ in order to identify the modular pattern. Note that there are no units in my set of configurations that are appropriate to be used for door and window sills or to protect the exposed top of the wall. Shapes with a sloping top surface (wash) and drip edge should be used in those locations, and my faced units don't include such features. Sills and wall caps are more appropriately made of cut stone or custom pre-cast concrete.

FIG. 10 shows a wall laid out using bonded units with straight-fronted facings and includes a 45° angled bay (10-1). FIGS. 10 a and 10 b are plan views of odd/even courses corresponding to the section marks placed on the front view. Note that openings have been included in the angled bay. Although the jamb units for those openings haven't been detailed to the extent other units have been, corner and fractional units for the angled bay would also be provided with finished jambs as needed, following the procedures already described. As with all of the bonded modular units, there is no difference in size or volumetric shape between specialized bay units with and those without finished jambs.

FIG. 11 shows a wall that includes curved portions using bonded units with bow-fronted facings. It illustrates a turret (11-1), bow (11-2), pilaster (11-3) and pillar (11-4). FIGS. 11 a and 11 b are plan views of odd/even courses. Note that openings have been included in the bow and turret. Although they haven't been detailed on the drawings to the extent other units have been, whole- and half-segment units with bow-fronted facings would also be provided in single- and double-jamb versions, with no difference in size or volumetric shape from those that have unfinished jambs. Lintel units with bow-fronted facings (with reinforcing steel curved to follow the curvature of the wall) would be used to span openings in curved walls, the same way lintel units with straight-fronted facings are used to span openings in rectilinear walls.

B. Concepts

Utilitarian Concrete Block: My invention enjoys benefits from incorporating already-manufactured utilitarian block. The manufacture of concrete block is a mature industry with well-regarded quality control capabilities that nonetheless continues to make incremental product and manufacturing improvements within the bounds of accepted standards. Block is mass-produced by forcing stiff low-slump concrete mixes into gangs of molds. The molds are promptly slipped off the uncured blocks without disturbing their shape and then the blocks are batch-cured in high-pressure steam autoclaves. Their relatively large size and light weight, afforded by their hollow, cored configuration, enables work crews to erect walls quickly and efficiently. Weighing against its economy is its unattractive coarse surface that results from the manufacturing process. The low-slump concrete mix used for making block also make it somewhat porous.

Quality Standards: Concrete block made and used in the United States is required by the building codes to conform to ASTM (American Society for Testing and Materials) standards. Standards are in place for hollow (50% void) and solid (25% void) load-bearing block and non-load-bearing block. For load-bearing block, the standard stipulates minimum face shell and web thicknesses, dimensional tolerances, concrete density, minimum compressive strength of blocks, maximum moisture absorption, maximum swelling from absorbed moisture and permissible moisture content at the time of delivery. A batch of block that has been successfully sampled and tested would not have to be re-tested after it has received the facing of my invention; thereby eliminating the risk that finished bonded units might have to be rejected because of failure to meet minimum physical properties.

Modularity: I have held it to be an absolute requirement that the bonded units I've developed work within the constraints of the modular system. Erecting walls using modular units laid out on module is the simplest, most straightforward way to avoid the need to cut-and-fit at the job site. The actual front face dimensions of the modular concrete blocks I incorporate into my invention are 15⅝″ long by 7⅝″ high. Allowing for an industry-standard ⅜″ mortar joint yields a module of 16″ in the horizontal by 8″ in the vertical, also known as the ‘nominal size’ of the block. This nominal size, 16″ by 8″, is the standard full-sized modular unit in this country. Internationally, a nearly identical 400 mm by 200 mm nominal size block is the modular metric equivalent; the actual size of the block allows for a 10 mm mortar joint. An 8″ wide (thick, front-to-back) block is actually 7⅝″ wide and so equals the 8″ half-module when the standard ⅜″ mortar joint is added. Thus, a nominal 8″ wide block allows the block work to stay on module as it turns right-angled corners.

Sizes and Configurations: Modular utilitarian block is manufactured in a variety of widths and core configurations, all of which can receive the bonded facings of my invention. Blocks are usually made with two or three cores. Core configurations are sometimes merely each manufacturer's preference, but sometimes they serve very useful purposes, such as avoiding the cores from showing on the ends of the block, accommodating vertical reinforcing steel (which is subsequently encased in grout), or enabling blocks to be conveniently cut in half on the job. Specialized units are also made that can accept horizontal reinforcing steel. The various core configurations and specialized units are manufactured in a range of nominal widths (thickness, front-to-back) from 4″ to 12″ in 2″ increments, and sometimes 16″. However, in order to stay on module, outside corners should be made from 8″ wide blocks (the half-module). With care an 8″ block can have a portion of the back cut away to form an L-shaped wrap-around corner for walls that are less than 8″ wide, as is often done with conventional block work. Special L-shaped blocks are sometimes available that accomplish this. Either of these solutions can receive a bonded facing:

Quality Block Widely Available: As stated earlier, and by way of elaboration here, the concrete block-making industry, as it now exists, has become highly standardized. This, despite the fact that block is manufactured by numerous companies supplying their local markets. They produce concrete block very economically that consistently meet the quality standards demanded by the building codes. Concrete block is ubiquitous, quite possibly found on every residential, commercial and industrial building project. My invention enables me to take those readily-available blocks, having been already quality-certified, and transform them into more attractive and possibly more durable building units with the added capability to construct angled bays with proper corners and smoothly curved walls. My bonded block assemblies offer another choice when designers or contractors consider using decorative concrete masonry or using non-structural brick or stone veneer to conceal and protect a utilitarian block back-up wall. They also offer a better way of constructing walls with unusual angles and curves.

Bonded Facings: For facings to be ‘bonded’, as I use the term, the facing material has to adhere to the already-manufactured block as it cures or sets into a solid. Facing material is applied, or cast, in a fluid or semi-fluid state that flows, conforming to the surface irregularities of the block. Upon curing, it forms a chemical and/or mechanical bond to the surface of the block. If necessary to improve the bond, a commercially available bonding agent can be applied to blocks before facings are cast.

Seamless Facings: For facings to be ‘seamless’, the facing material has to be applied to all surfaces and around any corners before the facing material has begun to cure or set. This affords the best chance for avoiding a visible difference between adjacent faces. This also eliminates ‘cold joints’, which provide an opportunity for moisture to penetrate into the surface. (The boundary between the facing material and the block to which it is applied is an example of a cold joint.)

Substantial Thickness: I have used the phrase ‘facing of substantial thickness.’ Elaboration is in order and the implications need to be considered. If more than ⅜″ of thickness is uniformly added to the front surface of a block, inside corners will no longer be able to stay within the modular system established for concrete masonry. The blocks converging at the inside corner will interfere with each other. On the other hand, a thin (less than ⅜″) facing offers little opportunity to create a meaningful depth-of-profile, and not nearly enough for the profile I prefer for my invention. The substantially thick (more than ⅜″) facing of my invention works within modular constraints because of the chamfered perimeter of the deep profile. So actually, the chamfered profile of the facing is very important. The 3/16″ facing thickness at the perimeter of the chamfered edge is also important because it provides enough facing material to assure that it can cure properly and bond to the block. As anyone in the concrete and plaster trades can attest, a feathered (tapered to zero thickness) edge of a cementitious overlay makes the edge susceptible to crumbling or breaking away. A feathered edge would likely be a problem with any kind of facing material. Furthermore, feathered edges on the chamfers would require far more precision in the casting process than can reasonably be achieved; after all, the ASTM dimensional tolerance for block is +/−⅛″.

Weather-Resistance: Masonry of all types—stone, terra cotta, brick and block—have similar physical properties and all are quite durable. Moisture is absorbed to some extent by all masonry and is the cause of long term deterioration. In northern latitudes, the absorbed moisture is subjected to damaging freeze-thaw cycles. Also of concern is attack from dissolved atmospheric chemicals that might be absorbed into the masonry such as acids or sulfates; and efflorescence, whereby salts or carbonates contained within the masonry form a harmless white crust on the surface when absorbed moisture evaporates. Highly absorptive masonry presents the added concern that moisture could be transmitted all the way through the wall. Concrete block is generally the most absorptive of the various kinds of masonry units. Concrete masonry exposed to the weather should be periodically treated with clear water repellents and I expect mine would need to be, too. The prototypical bonded units I have made are faced with mortar. As my invention is further developed, efforts will be made to assure that the faced units are much less absorptive than the block onto which the facing is bonded. Latex-fortified admixtures, superplasticisers, air-entraining additives and fiberglass filament aggregates are some of the enhancements that will be considered. Significant effort is expended worldwide to improve the weather-resistance and durability of concrete, so future progress in that regard can be expected.

Acoustical Applications: The deep profiles afforded by facings of substantial thickness suggest potential uses for acoustic control. Flat, hard wall surfaces can set up disagreeable echo or reverberation conditions. My invention can provide extremely deep profiles to diffuse sound waves reflected off walls—walls that also have to be durable, such as interiors of gymnasiums and factories, and exterior sound barrier walls alongside urban highways. Potential acoustic facing profiles include pyramid shapes and convex curves. Curved surfaces can be simple (curved in one direction, such as the bowed shapes I've illustrated) or compound (curved in two directions, like a bulb). When the entire wall is curved, that could provide additional low-frequency sound diffusion, which requires extra-large curved surfaces.

Molded Prototypes: I have successfully cast prototypical bonded block assemblies—stretchers, outside and inside corners and jambs. Molds are made of plastic, vacuum-formed over wooden patterns. To cast the facing, a mold is placed front face down and open side up to resemble a pan. The pan is filled with mortar (ASTM C270, Type S), agitated to dislodge any air pockets and the mortar screeded off even with the lip of the pan. After a mortar slurry is trowelled into the surface of the block to assure a good bond, the block is worked onto the mortar that fills the pan. In two days, the mortar is sufficiently cured to lift the completed unit out of the mold. An outside corner unit is molded front face down, same as a stretcher. After a block is worked onto the mortar in the pan, mortar is slushed down into the vertical leg of the mold that wraps around the end of the block to form the corner. The chamfered facet at the top of the mold is omitted in order to create a passage for mortar to be dropped in. Striking off with a trowel after the mold is filled finishes the un-formed chamfer. Molding is always done with the front face of the block oriented downward, except that the inside corner unit is molded standing on end. As a point of interest, a seamless facing on all four sides (front, both ends and back) is possible. In that instance the mold that surrounds the block is assembled sequentially as the facing material is placed around the block. The upper-most facet of the mold is left open as a passage in order to fill the mold with the last of the facing material, and the un-formed facet is struck off with a trowel.

Depositing Facings: Another method of producing the desired bonded facings could be ‘additive manufacturing’ (3-D printing), by which material is accurately deposited, layer by layer, to build an object without using molds. The palate of materials that can be deposited in this manner is growing. Additive manufacturing might soon make it possible to deposit onto concrete block seamless facings of the kind I envision. For convenience, I have referred to the process of applying the facings simply as ‘cast’ or ‘molded’.

Managing Numerous Configurations: As stated earlier, concrete block is available in a variety of core configurations (some necessary to serve a specific purpose), a range of widths (or thicknesses), and special purpose units designed to accommodate horizontal steel reinforcing. A building project invariably requires many of these different types of units. Proprietary units, including those that might be developed in the future, further compound the issue. As I have demonstrated, the bonded facings of my invention would also need to be supplied in a variety of configurations for corners and openings and, for more elaborate projects, bays and bows. The process of applying the facings after the blocks have been manufactured enables a wide range of facing configurations to be combined with a wide range of different block types without complicating existing manufacturing and supply channels. From a practical standpoint, I expect that the masonry contractor would determine the quantities (including an allowance for waste) of each type of block that should receive the bonded facing and the quantities needed of each facing configuration. The un-faced block would be delivered in those quantities to the location where the facings are to be applied. The facing material would be prepared in uniform batches in order to achieve a consistent appearance of the finished units. The facing process would eliminate any concerns that the various types of blocks, potentially obtained from multiple suppliers, might not match each other. The faced units would then be shipped to the job site, taking precautions to protect the formed surfaces from minor damage. The faced units would be laid up on the job with mortar in a conventional manner.

Laying Up Bonded Units: The shape and weight of the facing profile I prefer for my invention affect the installation of the units. Conventional block laid in mortar is first raised at the corners of the walls. A string line is then stretched between corners, positioned at the top front edge of the course being laid, and block is laid to fill in between the corners. The string line provides a reference for aligning the blocks vertically and front-to-back. My faced units' top-front beveled edge makes stringing the line and aligning units to the string line difficult. The beveled facing also makes for rather ambiguously struck mortar joints; the jointing tool has to run along wedged reveals between the units as opposed to well-defined block edges. As for the weight, an 8″ wide (thick) full-sized hollow load-bearing block weighs about 33 pounds. The mortar facing on a full-sized stretcher weighs about 10½ pounds. Aside from the obvious difficulty of handling an awkward shape and heavier unit, the facing also shifts the stretcher's center of gravity approximately 1⅛″ toward the facing. The Empirical Design chapter of the Building Code Requirements for Masonry Structures (ACI 530) stipulates that gravity loads must fall within the middle third of a masonry wall's width (thickness), otherwise design calculations are required to determine stability. The center of gravity for the 8″ wide (thick) faced stretcher falls just within the middle third, so the eccentricity of the units deserves consideration prior to their use. I have erected a sample wall consisting of nine faced stretcher units without much difficulty and with good results. 

1. I claim the enhancement of already-manufactured concrete masonry units by cutting units to the required size and shape when necessary and then casting, forming, molding or depositing additional material as a seamless facing bonded onto one or more surfaces before the units are utilized for construction; any surface selected to be faced receives the facing over every portion of that surface which would subsequently be exposed to view once the unit is mortared into place, leaving none of that particular surface of the original unit exposed; the facings being any that: A. are thicker or deeper than ⅜″ at the facing's apex when modular units (or non-modular units cut to modular sizes) are selected for enhancement and the perimeter of the facing profiles are sufficiently thin or tapered to enable the masonry units so enhanced to be used in accordance with the modular system, or B. wrap around a corner, producing a corner unit that converges at an acute or obtuse angle, or C. have a simple or compound curved surface. 